# RotaMeter correction factor

Hello Dear friends

i was doing tests to evaluate the performance of my Engine Test bench, (197/225cc engine 12.6kW IC SI engine, Propane) For mass flow rate i have used a rota meter to find the Volume flow rate and convert it to mass flow rate, i couldn't find a rotameter for propane so i decided to go for oxygen rotameter

now that i have got the values they are 4, 4.5, 4.8, 5 lit/min
as they are the indicated flow rates

for correction i have used these equations

Cdensity=(density of oxygen/density of propane)^1/2
Cpressure= (p+0.1013/ps+0.1013)^1/2
p=actual operating pressure
ps=standard or designed pressure for rotameter use
Ctemperature=(ts+273/t+273)^1/2
ts=standard temperature for rotameter use
t=actual operating temperature

Gas Correction factor(GCF)=Cdensity*Cpressure*Ctemperature
Actual Flow = Indicated Flow rate * GSF
the density of propane is 1.873g/lit
operating temperature was recorded as 10C
operating pressure was 0.005MPa
standard values for rotameter are 1.292g/lit, 20C, 0.343MPa

so the actual flow values are 1.688, 1.899, 2.0265, 2.111 lit/min

i just wanted to ask that is it correct method or am i missing something because when i evaluate the thermal efficiency of my test bench it gives me above 60% which is no way possible

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